Shelf life of Anti-Freeze?

[UncleS2]

I'm installing a new thermostat on my car tomorrow, & it's the perfect time to change the coolant. I have a full gallon of Prestone that's at least 5 yrs old, maybe a year or two older. Does anyone know of a good reason that I shouldn't use it, assuming no cooties show up in a clean glass jar, & or the bottom of the jug?

What, me, *Cheap*? I'm hurt!

 

[UncleS2]

Doh!

I've answered my own question at their website, I'll assume that "many years" is good for 5-7 years. Admins, feel free to edit or delete these posts.

 

[Patman]

No need to delete, it would be interesting to see how other's feel on this topic. I wonder the same thing myself, as I have a jug of premixed coolant in my garage that is about a year and a half old, and has already been opened.

 

[VaderSS]

From what I understand, there is a definite shelf life, once the container has been opened, especially if it has been mixed with water.

 

[Chris]

Mixed it will go bad. You will know when it does, but it seems like it took about a year or two.

 

[Patman]

The mixed stuff that I have actually came "premixed" though. Canadian Tire stores up here sell a premixed coolant (which is 60% coolant/40% water) I bought this for my wife's Honda since a drain and refill of her rad only takes about 2L or so, so I don't need a big huge 4L jug of coolant, which would then net me 8L if I mixed it. So instead I bought a 4L jug of the premixed stuff, used what I needed that time, and was saving the rest for the next time I drain and refill her rad (which is probably in the next month).

 

[OneQuartLow]

quote:

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Originally posted by VaderSS:
From what I understand, there is a definite shelf life, once the container has been opened, especially if it has been mixed with water.

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What? I hadn't heard this. With distilled water? I premix & carry a jug with me on trail runs just to avoid contamination. What would cause the aging? Specific Gravity hasn't changed but that's all I've checked.

David

 

[BOBISTHEOILGUY]

Several thoughts on this...

Possible seperation from the water over that period of time???? The other thing is to take a PH strip and check it's acidity, making sure it is still neutral. This is something you can do while in the vehicle to see if the acidity is high and if so, you need to change it or add an additive that will neutralize this. I use the Schaeffers Clean and Cool just so I don't have to worry too much about this.

 

[UncleS2]

Well, it's all done. My old thermostat was *broken*, probably has been since last spring.

First time I ever saw that.

Car has ~7 qt system, I used a gallon of distilled water to mix up 2 gal of coolant. Drained coolant, filled w/clean water, drove till warm(*Fast* w/ the new t-stat!), then drained that. Refilled w/50% mix and 4 oz RMI-25. Wish I'd known about the Schaeffer Clean & Cool last trip to Texarkana.

The first question at the Prestone FAQ is about shelf life. Says shelf life good for "many years" if still sealed(mine was

), also good for many years if opened & recapped, *If* no water was added. That surprised me. Oh well, I oughta be good for 2 yrs or so on coolant now. By then, it'll need a new timing belt, & it'll get a new water pump along with it- perfect time to change coolant again!

 

[pbm]

I put some A/F that I purchased in the early 90's (probably 1992) in my 97 Ranger last fall and it seems to be working fine. It sat unopened in my heated garage for over 15 years.

 

[txtruck]

anti freeze isnt what i would worry about going bad. its the additives that fight/ prevent corrosion. Think electrolysis and nothing to fight it off. Measure it on your car/ truck. It might surprise you!